System of electrical distribution.



J. L. WOODBRIDGB.

SYSTEM OF BLEGTRIGAL DISTRIBUTION.

APPLICATION FILED 11.14. 1909.

941,601 Patented Nov. 30, 1909.

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JOSEPH LESTER WOODBRIDGE, 0F PHILADELPHIA, PENNSYLVANIA.

SYSTEM OF ELECTRICAL DISTRIBUTION.

Specification of Letters Patent.

Patented Nov. 30, 1909.

Application filed April 14, 1908. Serial No. 489,876.

To all whom it may concern:

Be it known that I, Josnrn L. Woosnumon a citizen of the United States,and u resident of Philadelphia, in the county of Philadelphia. and Stateof Pennsylvania, have invented a. certain new and useful System ofElectrical Distribution, of which the following is n specification.

My invention relates to systems of electrical distribution in which astern bat tery is connected across a circuit ich is subject to widefluctuations of voltage, and in which it is desired that the storagebattery shall not ordinarily charge and dischar a with these voltagefluctuations but shal be so arranged as to remain at all times connectedto the circuit ready to discharge and take up the load on the circuit incase the normal source of current supplying said circuit should beinterrupted. As an example of such a system may the exciter circuit fromwhich current is furnished for exciting the fields of the generators inan electric power plant, the voltage on this cxciter circuit beingvaried automatically to maintain constant voltage .at the terminals ofthe generators with variations of load. It is frequently desired toconnect a storage battery across such an exciter circuit, but withoutthe interposition of s ial regulating devices such a battery wou dcharge whenever the voltage of the cxciter cilcuit rises, and woulddischarge whenever said voltage falls. The increase in voltage on theexciter circuit would be accompanied by an increase in current output tothe field circuits supplied thereby and any additional output for charing the buttcry would throw an additiona load on the source of excitingcurrent which is undesirable. it is however desirable that the batteryshould always be thus connected to the excitcr circuit in order to guardagainst even a momentary interruption of current in the field circuits.

The object of the present invention is to provide menus for controllin rthe operation of a battery connected as above described, so as toconliuc its charge and discharge within very narrow and nc'ligihlclimits under normal conditions am at the sumo time permit it todischarge without hintaken drcnce in case the normal supply of currentto the exciting current is interrupted.

The nature of my invention will be more clearly understood by referenceto the following description in connection with the accompanyingdrawing, in which 1-2 re resent the main conductors or bnsbars 0 anexciter circuit to which current is supplied by the enerators G and Gf,for exciting the field coils X and X. It is assumed that the voltageacross the busbcrs 1--2 is varied automatically by apparatus such as iswell known in the art for accomplishin this purpose. A storage battery Bwith a ster C in series therewith is connected across the busbars 1-2.The booster C is provided with a series coil F which is so connected asto produce a voltage in the booster U op osing the flow of currenttherethrough. liis 0011 alone might be made of a sulhcicnt number ofturns to produce the desired effect in preventing the battery fromcharging and discharging beyond a certain amount with variations ofvolts. across the busbars 12. In many cases owever, the number of turnsin the field winding F thus required would produce an exce inglyexpensive machine. A second coil 1? is therefore shown, the current inwhich is controlled by the carbon regulator A. This regulator is wellknown in the art consistin of two piles of carbon disks 11, u on wl icha lever L, beu rs in such n manner t mt pressure on one end of the loverwill increase the pressure on one of the piles and decrease that on theother. The ressure at one end of the lover is iroducer by a solenoid Dconnected into the battery circuit, the pull of this solenoid beingbalanced b an adjustable spring E at the other out A p0 lfll'lzllig coilQ is also shown connected across the battery terminals, which serves topolurlzc the core of the solenoid. Thus any [low of current through thecoil D in one direction will pull down on the lever while a low in theother direction will relicvc this pull. The two piles of carbon (llfilisare connected in series across the buttery terminals, while the holdcoil F is connected between the intermediate point in the circuitbetween the two carbon pilcsaud the middle point of the butler). A Howof current from the battery through the coil D in the dischargedirection, caused for example by a drop in the voltage across 1-2, willso change the relative rcssures on the two carbon piles H II antherefore their relative resistances as to cause a flow of currentthrough the coil F which will produce a voltage in the booster C adaptedto oppose the discharge current from the battery By properlyproportioning the parts of th1s apparatus a very small charge or dischare current in the battery circuit may be ma e to produce a voltage 1n thebooster sulficient to compensate for wide fluctuations of voltage on thecircuit 12.

Connected around the booster C is shown a circuit 37 containing theswitch K and a solenoid 0. When the switch K is closed this circuitserves to connect conductor 1 directly to the corresponding terminal ofthe batter thereby short-circuiting the booster C an permitting thebattery to discharge directly into the exciter circuit. flhe switch K isclosed by a solenoid R which is connected into a circuit leading fromone terminal of the battery by way of conductors 345-6 and 2 to theother terminal of the battery. There are two interruptions in thiscircuit at P and P which may be closed by contacts mechanicallyconnected to the corresponding generator switches M and M and are thusclosed when these generator switches are open. The circuit 4-5-6 istherefore comp etely closed onl when both generator switches M and areopen. be long as either generator G or G, is suplying the current to thecircuit there will e no current in the solenoid R and the switch K willremain o u. If, however, both switches M and h' are open so that thenormal sup ly of current from the ner ators G and (5 to the excitercircuit is entirely interrupted, current will flow through the solenoidR closing the switch K and connecting the batte directly across thebusbars 1-2 ermitting it to furnish the current supplied from thosebusbars. By closing the switch K a short circuit is established aroundthe booster. This latter is protected from an excessive flow of currentunder these conditions in two diliercnt ways. First, the effect of aflow of current in the field coils F and l (the latter bein pro duced bycurrent in the solenoid D will produce a booster voltage tending tooppose this flow of current. and limit it to a negligible amount. Secondthe flow of current in the solenoid 0 will open the switch N anddisconncct the booster.

What I claim is:

1. In combination, an electric circuit, a storage battery and itsboos-tor conncctcd thereto, and means responsive to lhc charge anddischarge of the battery and adapted to excite the booster to opposesaid charge and discharge.

2. In combination an electric current, a storage battery and its boosterconnected thereto, means responsive to the charge and discharge of thebattery and adapted to ex cite the booster to oppose said charge anddischarge, and means for short-circuiting the booster.

8. In combination, an electric circuit and its source, a store batteryand its booster connected across t c circuit, means res onsive to thecharge and dischar e of the attery and adapted to excite tie booster tooppose said charge and discharge, and means adapted to short-circuit thebooster when the current from the source is interrupted.

4. In combination on electric circuit and its source, a storage batteryand its booster connected thereto, means responsive to the batterycharge and discharge and adapted to excite the booster to oppose saidcharge and dischar e, and means adapted to shortcircuit the oosterll)0I1 an interruption of the connection from t e source to the circuit.

5. In combination on electric circuit, a plurality of generators,suitable switches for connecting t e generators to the circuit, astorage battery and its booster connected across the circuit, meansresponsive to the battery charge and discharge and adapted to excite thebooster to o pose said charge and discharge,a switch an appropriateconnections for short-circuitin the booster and means for closing saidswitch when all the generator switches are open.

6. In combination on electric circuit, a storage battery and its boosterconnected thereto, means responsive to the charge and discharge of thebattery and adapted to excite the booster to oppose said charge anddischarge, means adapted to short-circuit the booster, and meansresponsive to the current in the short-circuit for opening the circuitof the booster.

7. In combination an electric circuit, a storage battery and its boosterconnected thereto, means responsive to the charge and discharge of thebattery and ada ted to excite the booster to oppose said ciargc anddischarge, means adapted to short-circuit the booster when the currentfrom the source is interrupted, and means responsive to the current inthe short-circuit for opening the circuit of the booster.

8. In combination an electric circuit of varying potential and itssource, a storage battery connected thereto, means for prevcnting thebattery from responding to the variations of potential, and means orsuppressing the not ion of the preventive means when [he source isdisconnected from the circuit.

9. In combination a field toll, an electric circuit of varying potentialand its source 5 coil when the current from the source is inforsupplying current to said field coil, a terrupted. 10 storage batteryconnected to the circuit, In testlmony whereof I have hereunto means forpreventing the battery from resigned my name.

s ending to the variations of potential 'of JOSEPH LESTER WO0DBRIDGB.

t e circuit, and means for suppressing the Witnesses:

action of the preventive means and rmit- CLIFFORD K. CASSEL,

ting the battery to take the load of t e field F mm; E. Fnmzcn.

